Plant‐Derived Substances Used Against Beetles–Pests of Stored Crops and Food–and Their Mode of Action: A Review

Plants are sources of numerous active substances that are used to protect crops. Currently, due to the limitations of using synthetic insecticides, plant products have attracted increasing attention as possible pesticides. In this review, we discuss some of the most interesting plant products (for example, Solanaceae, or Asteraceae extracts, Artemisia absinthium or Citrus spp. essential oils, and single compounds like α‐chaconine, or α‐solanine) that exhibit insecticidal activity against beetles that are pests of stored food products. Next, we describe and discuss the mode of action of these products, including lethal and sublethal effects, such as antifeedant or neurotoxic activity, ultrastructural malformation, and effects on prooxidant/antioxidant balance. Furthermore, the methods of application of plant‐derived substances in food storage areas are presented.     

Heterologous expression of surface-active proteins from barley and filamentous fungi in Pichia pastoris and characterization of their contribution to beer gushing

The spontaneous over-foaming of beer upon opening, i.e. beer gushing, is an unwanted phenomenon for the brewing industry. Currently, surface-active proteins from filamentous fungi and non-specific lipid transfer proteins (nsLTP1) from barley are discussed as gushing inducers. In our study the class I hydrophobin FcHyd3p from Fusarium culmorum, the class II hydrophobin Hfb2 from Trichoderma reesei, the alkaline foam protein A (AfpA) from F. graminearum and nsLTP1 from Hordeum vulgare cv. Marnie (barley) were heterologously expressed in Pichia pastoris and used in gushing tests. The class I hydrophobin FcHyd3p was unable to induce gushing in beer. The class II hydrophobin Hfb2 was able to induce gushing in beer, but proved to be inhibited by heat treatment as well as by the presence of enriched hop compounds. Both resulted in a reduced gushing potential. AfpA and nsLTP1 exhibited no gushing-inducing potential at the amounts added to beer. Addition of these proteins to beer or carbonated water previously treated with class II hydrophobins revealed a gushing reducing character.     

Influence of physiological and chemical factors on the absorption of bioactive peptides

Food-derived bioactive peptides can be released during digestion and have a potentially beneficial effect on human health. It is known that the penetration of peptides across the small intestine can take place in several ways. The research related to the bioavailability of peptides develops dynamically, but still raises many doubts. Since there are many barriers to absorption of peptides, there is still a need to carry out in vitro and in vivo investigations on the bioavailability of these compounds. Moreover, there are few in vivo studies regarding the absorption and activity of peptides in organs, hence the lack of unequivocal and reliable information about this process. Therefore, this review discusses the current research on in vitro and in vivo absorption of these compounds and factors that play a key role in this process and provides better understanding of the in vitro and in vivo bioavailability and bioaccessibility of peptides.     

Effect of plasma sizing on basalt fibers adhesion with wood-working resins

European Journal of Wood and Wood Products - Basalt fabric with manufacturer-made silane sizing was additionally treated by propane-butane enriched atmospheric pressure nitrogen plasma for 15 and...     

Colour change with longitudinal compression supports hypothesis of multilayer interference as cause for meat iridescence

The mechanism of iridescence in meat and meat products is still not fully understood but a widely accepted hypothesis is that it originates from a multilayer interference from sarcomere discs. In multilayer interference, the reflected wavelength is affected by the refraction angles, the thicknesses and refractive indices of the intermittent layers. A variation of these factors should therefore cause a disappearance or shift of iridescent colours. To test this hypothesis, we progressively compressed iridescent rolled fillets of ham longitudinal to the long axes of the muscle fibres and measured the interference colours by reflection spectrophotometry. We observed an interference colour shift from longer to shorter wavelengths and reflection intensity decreased with increasing compression pressure. Our data indicate that the compression decreased the layer thickness, so that constructive interference occurred at shorter wavelengths. The results thus provide support for multilayer interference being a primary cause and mechanism for meat iridescence.     

Influence of hydrophobic and hydrophilic filler particles on thermal expansion and cooking loss in meat protein gels

This study aimed to determine the effect of replacing hydrophobic fat-based particles with hydrophilic inert glass particles at concentrations 10%, 25% and 40% on expansion, contraction and cooking loss of meat protein gels during heat treatment up to 85 °C. Incorporating glass particles resulted in gel expansion (up to 22.3% ± 2.8% at 40%) independent of the particle concentration during heat treatment in an open system, while an increased fat-particle content provoked a gel shrinkage (up to −6.5% ± 2.2% at 40%). At high filler concentrations, expansion and shrinkage were inversely correlated with cooking loss: The highest fat and glass particle filler concentration exhibited the lowest cooking loss (20.1% ± 0.5% for glass particles and 21.7% ± 0.2% for fat particles) despite the observed extensive structural changes, which was related to particle hydrophilicity, gel composition and structural rearrangement. These results will be helpful to design particle-filled composite meat gels with different types of particles.     

Effect of lyoprotectants on β-glucosidase activity and viability of Bifidobacterium infantis after freeze-drying and storage in milk and low pH juices

The benefit of disaccharide protectants for maintaining viability and β-glucosidase activity of Bifidobacterium infantis UV16PR during freeze-drying and storage in different food matrices was investigated. Protectants used were cellobiose, lactose, sucrose and trehalose.     

Accidental and deliberate microbiological contamination in the feed and food chains--how biotraceability may improve the response to bioterrorism

A next frontier of the global food safety agenda has to consider a broad spectrum of bio-risks, such as accidental and intentional contaminations in the food and feed chain. In this article, the background for the research needs related to biotraceability and response to bioterrorism incidents are outlined. Given the current scale of international trade any response need to be considered in an international context. Biotraceability (e.g. the ability to use downstream information to point to processes or within a particular food chain that can be identified as the source of undesirable agents) is crucial in any food-born outbreak and particular in the response to bioterrorism events. In the later case, tested and proven biotraceability improves the following: (i) international collaboration of validated tracing tools and detection methods, (ii) multi-disciplinary expertise and collaboration in the field of food microbiology and conceptual modeling of the food chain, (iii) sampling as a key step in biotracing (iv) optimized sample preparation procedures, including laboratory work in Biosafety level 3 (BSL-3) laboratories, (v) biomarker discovery for relevant tracing and tracking applications, and (vi) high-throughput sequencing using bio-informatic platforms to speed up the characterization of the biological agent. By applying biotraceability, the response phase during a bioterrorism event may be shortened and is facilitated for tracing the origin of biological agent contamination.     

The challenge of monitoring impacts of water abstraction on macroinvertebrate assemblages in unregulated streams

Monitoring of the ecological impacts of water abstraction from unregulated streams in the state of New South Wales (NSW), Australia, is challenging because water is abstracted by thousands of geographically dispersed users who pump intermittently according to temporally varying needs and the limitations imposed by licences and access rules. Detailed, quantitative monitoring methods are too costly for widespread routine application because of the size of the state (801 000 km²) and the large number of streams affected by abstraction. We therefore tested the possibility of detecting abstraction impacts on aquatic macroinvertebrates with rapid biological assessment (RBA) methods similar to those that are routinely used for biological monitoring of Australian rivers. We sampled 85 sites on unregulated streams in north‐eastern NSW during a period of prolonged and recurring drought, 54 of which were designated as reference sites with respect to water abstraction because upstream entitlement for abstraction was less than 1% of their mean annual flow (MAF). The remaining, non‐reference sites had an average of 4% of MAF licensed for upstream abstraction (range 1–20%). Sweep and kick samples were collected at each site in two seasons, and invertebrates were picked for 30 min per sample and analysed at genus level. We found a small but statistically significant overall difference in macroinvertebrate assemblages between the reference and non‐reference sites, but the amount of upstream entitlement did not affect the degree to which assemblages at individual sites deviated from site‐specific reference conditions. We attribute the absence of evident impact mainly to the low proportions of streamflow abstracted, but limitations of RBA methods may also be a factor. We recommend a risk‐based approach to future monitoring whereby effort is focussed on those streams where a high proportion of flow is abstracted. Copyright © 2009 John Wiley & Sons, Ltd.